Refrigerant control system



Dec. 12, 1950 H. J. MATTESON REFRIGERANT CONTROL SYSTEM Original FiledApril 29, 1941 C'ONDENS/NG I II ffaeom [114 77550,

INVENTOR.

Patented Dec. 12, 1950 2,533,600 REFRIGEBANT CONTROL SYSTEM Harold J.Mattcson, Glendale, Calii'., assignor to General Controls 00., Glendale,Calii'., a corporation of California Original application April 29,1941, Serial No.

390,914, now PatentNo. 2,363,010, dated November 21, 1944. Divided andthis application September 13, 1944, Serial No. 553,883

1 This invention relates to improvements in refrigerant-control valvesof the thermal expansion type; the present application being a divisionof my copending application, Serial No. 390,914, filed April 29, 1941;now Patent No. 2,363,010, issued November 21, 1944.

When a valve of the type indicated is installed in a refrigeratingsystem, on account of the nonlinear pressure-temperature curve ofconventional refrigerants, the valve must be manually adjusted for theparticular. average cooling temperature desired in the system. Thisnecessitates the constant attention of an experienced service man, overa period of possibly several hours, until the system is stabilized. Itis therefore a main object of this invention to overcome this difficultyby providing a valve whereby the superheat of the refrigerant at theoutlet of an evaporator fed by the valve is automatically maintainedsubstantially constant over a wide range of operating temperatures.

Another object is to provide a valve of the type indicated which, in thecontrol of a refrigerating system, requires no manual adjustment over awide range of operating temperatures.

Another object is the provision of a refrigerant control valve of thetype indicated whereby, upon initiation of operation of the system, ahigh degree of super-heat is provided so that overloading of the systemis prevented.

Another object is the provision, in a valve of the type indicated, ofadditional temperature responsive means for varying the effect of thetemperature responsive means normally controlling the operation of thevalve.

Another object is the provision of thermostatically controlled means forvarying the force normally urging the valve closure member toward closedposition.

Other objects and advantages of the invention will be found in thedescription, the drawing, and the claims; and, for full understanding ofthe invention, reference is to be had to the following detaileddescription and accompanying drawing, wherein:

Figure 1' is a longitudinal sectional view of a valve embodying theinvention and shown schematically, connected in a conventionalrefrigeration system; and

Figure 2 is a transverse section taken along the line 2-2 of Fig. 1.

In the drawing, the numeral 5| indicates a valve casing having an inlet52 and an outlet 53 separated by a partition 54. Threaded in an openingin the partition is a member 55 having .4 Claims. (Cl. 62-127) a portopening 56 therethrough which interconnects said inlet and outlet.Cooperable with a seat formed at the lower end of the port opening, tocontrol refrigerant flow through the valve in the direction indicated bythe arrows, isa ballshaped'closure member 51 which is urged towardclosed position by a compression spring 58, the upper end of the springcarrying a disk .59 pro vided with a central depression for receivingthe ball 51, the lower end of the spring bearing against an internalshoulder formed in a hollow extension 60 threaded in the inlet of thevalve casing. Within the extension 60 is a strainer ll' attached to,afitting 42. Provided for the actuation of the closure member is a rod6|, the bottom end of "which abuts the ball 51. The rod extends freelythrough the port 56 and its upper end portion is guided in a bore formedin the reduced upper end portion 6-2 of the port member 55, lateralopenings 63 being provided in that portion of the port member for fluidcommunication between the port and the outlet 53.

For operating the valve there is a fluid pressure motor which comprisesa flexible metallic diaphragm 64 secured, above a recess 65 formed inthe upper end portion of the casing, by a cover 66; a thermal bulb 61being connected by a pipe 68 to an opening formed in the center of thecover. The thermal bulb is preferably charged with a volatile fluid, thepressure of which is applied to the chamber defined by the diaphragm andthe underside of the cover so that with increase of bulb temperature thediaphragm is forced downwardly. Below the diaphragm is a pusher plate 69which has on its underside an integrally formed cylindrical extension 10which extends through and is guided in'an opening in a wall II whichseparates the chamber or recess 65 from the outlet 53. Also formed inthe wall II is an equalizer port 12.

Interposed between the adjacent ends of rod GI and pusher-plateextension 10 is one end portion of a bimetallic member 13 formed ofrelatively heavy strip material. The other end portion of the bimetallicmember is wound in the form of a spiral and is held at its extremity bythe bifurcated portion of a rod 14. This rod is mounted by its ends inthe side walls of a hollow extension member 15 secured to the side 01'the casing and in communication with the outlet thereof. As is seen inFig. 2, one end of rod 14 extends through the wall of member and isprovided with a squared portion 16 whereby the rod may be turned toadjust the tension of the bimetallic member, the rod after adjust- 3ment being secured in position by solder TI. The bimetallic member 13 isso constructed and arranged that, upon rise of temperature, the force,exerted by it on member ID in an upward direction, is increased.

In use in a refrigerating system, the outlet of the valve is connectedto the inlet of the evaporator 18, so that the temperature of therefrigerant wherein bimetallic member 13 is immersed is substantiallythe same as that at the inlet of the evaporator. The thermal bulb 61 ismade responsive to the temperature at the outlet of the evaporator 18 sothat the valve is operated generally in a conventional manner. However,due to the varying bias produced by the bimetallic member in accordancewith variation of temperature at the inlet of the evaporator, theoperation of the valve is so modified that substantially constantsuperheat of the refrigerant is automatically maintained. It is to benoted that if the ball 51, the rod GI and the adjoining portion ofbimetallic member 13 were mechanically united, it would be possible todispense with the bias spring 58.

The embodiment of the invention herein shown and described is obviouslysusceptible of modification without departing from the spirit of theinvention, and I intend therefore to be limited only by the scope of theappended claims.

I claim as my invention:

1. In a refrigerant control system: the combination with an evaporatorof a thermostatically controlled expansion valve for controlling pas.-sage of refrigerant to said evaporator; said valve comprising: a casinghaving an inlet chamber, and an outlet chamber for connection to theinlet of said evaporator; a partition separating said chambers andhaving a valve port therethrough; a closure member cooperable with saidport for controlling passage of refrigerant through the valve; a fluidpressure motor for operating said closure member in accordance with thetemperature at the outlet of said evaporator; and a bimetallic member insaid outlet chamber, and responsive to the temperature of therefrigerant therein, for modifying the action of said motor.

2. In a refrigerant control system: the combination with an evaporatorof a thermostatically controlled expansion valve for controlling passageof refrigerant to said evaporator; said valve comprising: a casinghaving an inlet chamber, and an outlet chamber for connection to theinlet of said evaporator; a partition separating said chambers andhaving a valve port therethrough; a closure member cooperable with saidport for controlling passage of refrigerant through the valve; means,adapted to respond to the temperature at the outlet of said evaporator,comprising a fluid pressure motor urging said closure member toward openposition; resilient means urging the closure member toward closedposition; and means, comprising a bimetallic memher mounted in saidoutlet chamber and responsive to the temperature of the refrigeranttherein, for varying the resultant of the opposing forces produced bysaid urging means; variation of the forces produced by the individualtem perature-responsive means, due to temperature variations in the samesense, being in opposition.

3. In a refrigerant control system: the combination with an evaporatorof a thermostatically controlled expansion .valve for controllingpassage of refrigerant to said evaporator; said valve comprising? acasing having an inlet chamber, and an outlet chamber for connection tothe inlet of said evaporator; a partition separating said chambers andhaving a valve port therethrough; a closure member cooperable with saidport for controlling passage of refrigerant through the valve; a fluidpressure motor for operating said closure member in accordance with thetemperature at the outlet of said evaporator; and an elongatedbimetallic member mounted by one of its ends in said outlet chamber \andresponsive to the temperature of the refrigerant therein, the other endportion of the bimetallic member being interposed betweensaid motor andsaid closure member.

4. In a refrigerant control system: the combination with an evaporatorof a thermostatically controlled expansion valve for controlling passageof refrigerant to said evaporator; said valve comprising: a casinghaving an inlet chamber, and an outlet chamber for connection to theinlet of said evaporator; a partition separating said chambers andhaving a valve port therethrough; a closure member cooperable with saidport for controlling passage of refrigerant through the valve: means,adapted to respond to the temperature at the outlet of said evaporator,comprising a fluid pressure motor urging said closure member toward openposition; resilient means urging the closure member toward closedposition; and means comprising an elongated bimetallic member mounted byone of its ends in said outlet chamber and responsive to the temperatureof the refrigerant therein, the other end portion of the bimetallicmember being interposed between said motor and said closure member;variation of the forces produced by the individualtemperature-responsive means, due to temperature variations in the samesense, being in opposition.

HAROLD J. MATTESON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Fonseca Oct. 23, 1934

